# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def reverseList(self, head):
        """
        :type head: ListNode
        :rtype: ListNode
        """
        b = head
        arr = []
        while(True):
            if b != None:
                arr.append(b.val)
                b = b.next
            else :
                break
    
        b = head
        for i in range(len(arr)-1,-1,-1):
            b.val = arr[i]
            b = b.next
        
        return head
        